The following relates generally to wireless communication, and more specifically to operating communication systems using both licensed and unlicensed frequency bands. Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple mobile devices. Base stations may communicate with mobile devices on downstream and upstream links. Each base station has a coverage range, which may be referred to as the coverage area of the cell. Small cells are increasingly being deployed to address wireless capacity and coverage limitations in cellular networks. In some cases, small cells cannot be connected to a wireless network through a dedicated wired backhaul. Non-line-of-sight (NLOS) wireless backhaul presents one possible solution; however, both licensed and unlicensed spectrum each present challenges to wireless backhaul implementations. For example, licensed spectrum may have limited availability, and its use may be cost prohibitive. Unlicensed spectrum, while possibly more readily available than licensed spectrum, may be susceptible to burdensome interference.